the kinetics and mechanisms of the substitution reactions of trans-[co(en)2cncl]+ with unidentate anions,  , cn¯, i¯,  , br¯ and scn¯ in 60% v/v dmf-h2o binary solvent at 40.0±0.2 °c were studied spectrophotometrically. an id mechanism was assigned for the replacement of chlorine by , cn¯ and i¯, an ia one for the entry of  and scn¯, and a d mechanism for br¯ entry. comparing the interchange ra...

poly (vinylpyrrolidone)-grafted silica as an organic-inorganic hybrid material was used as an effective heterogeneous polymeric cosolvent catalyst in organic reactions. this modified silica catalyzed nucleophilic displacement of alkyl halides for easy preparation of alkyl thiocyanates, alkyl cyanides, alkyl azides and alkyl aryl ethers. furthermore, the catalyst was applied for the conversion o...